DESCRIPTION

Controller LB-474 is a microprocessor temperature or humidity
regulator. The regulator can be used for controlling such devices as
i.e. a wood drying chamber, an injection moulding machine, an
incubator, a hot bath etc.

The device’s thermometers perform measurement of two temperatures
using the outside sensors with a platinum thermoresistor Pt1000 (or
optionally Pt100). Using the platinum thermoresistors assures high
measurement accuracy and constant thermometer characteristics. The
outside temperature sensors are made in the casings adjusted in
construction to individual requirements. Different
versions of the sensor casings allow on
measurement of different media in various scopes of temperatures. Two
thermometers can also create a psychrometer (based on a principle of
the wet bulb and dry thermometers) what allows on measurement and
regulation of air temperature and humidity independently. The
temperature sensors are attached to the regulator using two or four
cables with the clamps.

Temperature measurement path is calibrated by a producer and the
calibration data is stored in the panel in a digital form. The
controller does not have any mechanical calibration elements (i.e.
potentiometers). The device’s calibration is performed by sending the
calibration data obtained in the standard climate conditions through a
digital interface to a non-volatile calibration memory of a
thermometer. It guarantees comfort and high calibration accuracy as
well as stability of the device’s meteorological parameters in time.

The user has a possibility of (by using two key buttons) setting the
required work parameters in the regulator. The regulation works based
on PID algorithm. PID regulation parameters can be set by the user,
after attaching the regulator to a PC computer (on which a special
service program had been started) or from a keyboard.

The regulator LB-474 has five control outputs with the transistor
key outputs, designed for controlling the external transmitters in
(i.e. in a form of an external transmitters of block LB-475).
Optionally it can have an analogue output 0..10V or 4..20mA for
controlling other devices.

Through a series voltage interface RS-232 the device can be attached
to any computer system, what allows on remote collection of the current
measurement results.

The device is designed for application in stationary conditions, its
casing has attachments allowing on assembly on a standard rail TS35.
The panel has a big, easy to read LED display allowing on display of
two temperatures: set (10 mm) and intended (25 mm). The device is
powered from the energy network 230V.

Level of environment corrosion
aggressiveness according to PN-71/H-04651

B

Class of resistance according to DIN40050

IP40

*) - Going beyond recommended constant work conditions (i.e. when
installing a device in the open space) requires applying additional
safety means for the device's electronic parts protecting from water
out dropping inside the device (application of an additional outside
casing).

INTERFACE I - voltage

INTERFACE FUNCTIONS I

Possibility of reading the measurement results and storing the device's
calibration results in its non-volatile memory.

INTERFACE II - current

Series so called
digital current loop, 1 line
TXD (TXD line active status complies with 25 mA current, in the rest
stage 15 mA), transmission parameters time in accordance with RS232C:
300 bps, 7 bits of information, without evenness control, 1 stop bit.

INTERFACE FUNCTIONS II

Possibility of sending the measurement results automatically to long
distances in big measurement systems (i.e. to a multi-sensor climate
supervision system -
see LB-473). Output
with a galvanic isolation.

OVERALL DIMENSIONS

Attention: The device should be installed
inside an additional outside casing, i.e. wall switch gear. Climate
category of the additional outside casing has to be adjusted to the
conditions dominating in the place of installation. No cables are
supplied with the device (including a power supply cable) as an
installation component for only an authorized person.

A system of controlling a wood drying room is supposed to maintain certain humidity and temperature parameters set by a user for the process of wood drying, what optymalized the process of drying. For his purpose a controller cooperates with the throttling valve servos of hot air inlet and the chimneys outlet.